Snap switch



W. L. BUTLER Aug. 23, 1932.

SNAP SWITCH Filed Jan. 18, 1930 5f 1 v ,27 y

Patented ug. 23, 19.32

UNITED STATES PATENT OFFICE" WILLIAM L. BUTLER, 0F SCHENECTADY, NE'W YORK, ASSIGNOR TO WEBER ELECTRIC I COMPANY, 0F SCHENECTADY, NEW YORK, A CORPORATION OF NEW 'YORK SNAP SWITCH i Application filed January 18, 1980. Serial No.`421,780.

This invention relates to electrical switches and more particularly to the type known as snap switches. t

The important object of this invention 1s to provide a simple and eilicient snap switch, the parts of which may be manufactured and assembled without requiring the time and care heretofore found necessary in manufacturing and assembling the parts of such switches, thereby y providing for a reduced cost of manufacture without sacrificing the efficient operation of the switch.

One of the features making this possible is the provision of means to restrain the lateral movements of the oscillatory switch arm, so it will be accurately guided into and out of engagement with the stationary contacts with which it is adapted to cooperate to turn the switch on or off.

Another feature providing for the accomlishment of this object is to provide means or fixing and retaining the contact ends of t the stationary contacts against accidental movement or deflection whereby the are retained accurately in the path of t e oscillatory switch arm.

Other objects and advantages of the inven tion will become apparent during the course of the following description.

In the accompanying drawing forming a part of the description and wherein like numerals are employed to designate like parts throughout the several views:

Figure 1 is a longitudinal section through the switch.

Figure 2 is a top plan ofthe switch body or casing of insulating material.

Figure 3 is a transverse section of the same taken on the line 3-3 of Figure 2 with a portion of the snap switch or toggle mechanism `illustrated in dotted lines in operative position therein;

Figure 4 is a perspective view of the oscillatory yoke and switch or commutator blade ada ted for association therewith, and

Figure 5 is a perspective view of a modified form of commutator blade.

Referring now more particularly to the drawing, the numeral 5 designates the casing of the switch 'which is usually a body constructed from porcelain or other suitable insulating material. This body is provided with a cavity 6, the side walls of which are equipped wlth grooves 7 having V-shaped bottoms forming seats for the laterally extending trunnion arms 8 of a U-shaped oscillatory yoke 9 yforming a part of the snap or togg e mechanism well known in this type of switch. This oscillatory yoke is operated by a rocking Aactuator 10 pivoted as at 11 to the intermediate portion of a bridge plate 12 secured to the casing to span the top of the cavity 6 and secured to the walls of the casing in the well known manner. The connection lbetween this rocking lever 10 and the oscillatory yoke is provided b the well known type of spring,`not shown, a apted to enga e around the projection 13 provided on t e oscillatory yoke 9 whereby movement of the operating lever 10 to on and oi positions, causes the oscillatory yoke member to swing longitudinally of the cavity on its trunnion portions 8.

Adapted to be mounted on either or both trunnions 8, depending upon whether a single or double pole switch is desired, is an oscillatory commutator or switch arm designated in its entirety by the numeral 14. This switch arm, as usual, consists of a pair of resilient conductor blades 15 bound together at their central portions by a pair of insulators 16 clamped to the exterior surfaces of the two blades whereby the outer juxtaposed ends 17 may be sprung apart as the blade moves into engagement with stationary contacts to rmly embrace the same and establish an eilicient electrical connection. In distinction to the commutator blade assemblies heretofore employed, a tubular metallic rivet 18 extends through the insulators 16 and the central portion of the switch blades 15 to clamp the insulators to the blades.V This tubular rivet is insulated in any suitable manner from the conductor switch blades 15. The

. opening 19 through the tubular rivet is of assembly when mounted upon a trunnion 8 is loose thereon and consequently has considerable lateral play which permits of the free ends of the switch blade assemblies moving into pro er engagement with tlie contacts andena les the quick assembly of these blades with the oscillatory yoke without requiring the exercise of any great care or attention to fine dimensions `of the varlous parts. As stated previously, these improvements may be applied to either single or double pole switches and in the present illustration, the switch casing has been illustrated with provision for two pairs of stationary contacts while only one switch assembly has been illustrated as associated with the casing, for it is obvious that if a double pole switch is desired, another switch blade assembly 14 is provided for the other trunnion 8 of the oscillatory yoke and an additional pair of stationary cont-acts fitted up for thelr association with the opposite side of the casing.

The stationary contacts adapted to be ixedly secured to the insulator casing are indicated at 2O and 21 for attachment at opposite ends of the casing by means of the usual screws 22 extended from the back of the casing in the well known manner. Each of these stationary contacts is provided with a binding post opening, the formation of which provides the underside of each contact with an annular burr 23 surrounding the threaded opening and is adapted to lit an opening 24 provided in the casing for-the reception of the lower end of the binding ost 25.

The stationary contact 21, as best seen in Figure 1, is provided with an elongated angularly disposed portion 26 which is adapted to depend and extend down to substantially the bottom of the cavity 6 where it is free and a portion 27 which makes contact with the switch blade 15, is angularly disposed and fitted within the depression or groove 28. This securely retains the engaging end 27 of the stationary contact in fixed relation with respect to the casing.

The other stationary contact 2() overhan ing the edge of the cavity in the casing 1s equipped with a depending wing 29 which is adapted to iit in a groove or recess in the adjacent wall of the cavity to prevent the contact from turning upon its screw as well as to retain the contact making end of this contact in fixed relation with respect to the casing.

Having fixed the stationary contacts against movement, it now remains to fix or restrain the movements of the oscillatory switch blade so as to insure its perfect sliding contact with the stationary contacts in order to provide for the eiiicient and unfailing operation of the switch. It will be remembered that the switch blade assembly 14 has loose connection with, and lateral play upon, the trunnion 8 of the oscillatory yoke, and in order to restrict these lateral movements to insure contact of the blade 15 with thestationary contacts, the outermost insulator 16 is rovided with a depending projection in the orm of a segment or fan-tail 30, some portion of which is adapted to always be disposed in a groove 31 provided in the bottom wall of the cavity 6, regardless of the position of the switch blade assembly. It is to be noted that the segmental projection 30 is tted loosely within the groove 31 so that the side walls thereof guide 4the segmental projection and thereby restrain the lateral movements of the switch blade assembly upon its trunnion to such an extent that the switch blades 15 are prevented from contacting with the side wall of the cavity and at the same time are accurately guided into and out of engagement with the stationary contacts 20 and 21. One of these guide grooves 31 may be provided at each' side of the casing so that provision is made for adapting the device to a double pole switch instead of a single pole, as illustrated. l

In Figure 5, a modiied form of guide for the commutator blade assembly is shown, and in which, parts corresponding to those shown in Figure 4 have corresponding reference numerals with prime coeicients. The only difference between these two modifications is that, in Figure 5, the guide extension 32 lis formed of metal and as extensions of the contact blades 15 instead of an extension of the insulator block 16 a pair of which are secured to opposite sides of the assembly by the tubular rivet 19. The extensions 32 are of segmental or dove-tail shape and one is formed upon each of blades 15. These extensions are aligned and disposed in face to face contact to operate in a groove similar to the groove 31 for guiding the contact portions 17 of blades 15 into proper engagement with the stationary contacts 2O and 27.

These modifications of the casing. and switch mechanism provide for a less expensive manufacture of this type of switch by reason of the fact that the grooving of the casing eliminates the necessity of work incident to the care which must be exercised in the manufacture of switch blade assemblies and their more or less tedious attachment to the oscillatory yoke when they are securely fixed thereto as has been the customary practice heretofore.

It is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claims.

I claim:

l. In a snap switch, the combination with a casing having a cavity therein and a groove in the bottom wall of the cavity, contacts at the ends of said casing, a snap switch mechanism arranged in said cavity and including an oscillatory switch arm loosely connectedA 4a casing having a cavity therein and a groove in the bottom wall of the cavity, contacts at the ends of said casing, a snap switch mechanism arranged in said cavity and including an oscillatory yoke, a switch armloosely mounted on said yoke for lateral movements thereon, and said switch arm including a member provided with a segmental extension disposed in said groove and adapted to engage the side walls thereof to restrain lateral movements of said switch arm.

3. In'a snap switch, the combina-tion with a casing comprising an insulating body having a cavity therein and a groove in the bottom wall thereof, said bottom wall having a depression therein conductor contacts at the ends of said bod one of said contacts having an extension fitted in said depression, a snap switch mechanism arranged in said cavity and including an oscillatory switch arm loosely connected to said snap switch mechanism for lateral movements; said switch arm including a member provided with an extension operating in said groove and adapted to engage the s1de walls thereof to restrain lateral movements of said switch arm.

4. In a snap switch, the combination with a casing having a cavity therein, a groove in the bottom wall of the cavity, contacts vat the ends of said casing, a snap switch mechanism arranged in said cavity and including an oscillatory switch arm loosely connected to said snap switch mechanism for lateral movements, and said switch arm including an integral extension having itslower edge arcuated for reception in said groove and adapted to engage the side walls thereof to restrain the lateral movements of said switch arm.

5. In a snap switch, the combination with a casing havlng a cavity therein, a groove in the bottom wall of the cavity, contacts at the ends of said casing, a snap switch mechanism arranged in said cavity and including an oscillatory switch arm looselyy connected to said snap switch mechanism for lateral movements, and an element of insulating material secured to the intermediate portion of said switch arm and having its lower edge arcuated for operation in said groove and adapted to engage the side walls thereof to restrain the lateral movements of said switch arm, i

6. In a snap switch, the combination with a casin having a cavity therein and a groove 1n the ttom wall of the cavity, contacts at the ends of said casing, a snap switch mechanism arranged in said cavity, and including an oscillatory U-shaped yoke having a laterally projecting arm arranged above said groove, a switch blade having a ioat-ing connection upon said lateral extension, and said switch arm including a member extended toward said groove and having an arcuated lower edge for reception therein, whereby said extension engages the side walls of said groove to restrain the lateral movements of said switch blade.

In testimony whereof I have hereunto set my hand.

WILLIAM L. BUTLER. 

